It is desirable in a variety of applications to provide a lavatory faucet which turns on and off automatically, so that the user does not have to touch the faucet to operate it.
Electrically operated solenoid valves are known for use in sensor faucets. However, in a typical faucet of this type, an electric current is applied to an electromagnetic coil of a solenoid actuator to maintain a conventional solenoid valve open. Upon removal of the electric current, a spring forces the solenoid to close the valve. As a result, solenoid valves use a considerable amount of electricity to maintain them in an open position which makes them impractical for battery powered operation.
This invention relates in part to the use of modular in-line screens in a sensor faucet. Non-modular in-line screens have been used in faucets. For example, U.S. Published Patent Application 2004/0089350 to Marty et al. teaches in-line screens for thermostatic valves. The publication discloses a unitary valve body 22 with adjustable flow control assemblies 24 in the hot and cold water inlets 25 and 25a, respectively, to temper water through the valve (paragraph 022 and FIG. 2). Between the flow control assemblies 24 and the valve mixing chamber 26 are removable in-line screen assemblies 21 to filter out unwanted particulate matter (paragraph 0026 and FIG. 1). However, the in-line screens and flow control assemblies are not modular as contemplated by this invention.
U.S. Pat. No. 5,085,399 to Tsutsui et al. discloses a sensor operated faucet with separate piezoelectric actuators and associated diaphragms for each water inlet 130, 131. Each actuator diaphragm is separately controlled to regulate the temperature of fluid exiting the faucet (See col. 16, lines 3-11). A temperature sensor 170 in the water outlet piping 124 feeds a signal to the respective solenoids to control temperature (col. 17, lines 47-59 and FIG. 23). According to this patent, the mixing of hot and cold water is variously described as occurring in the outflow passage 124 (See column 15, lines 58-66 and FIG. 23) and in a T-shaped passage 134 adjacent the actuators and communicating with the outflow passage 124 (see column 16, lines 19-31 and FIG. 24). The operating components of this faucet are not modular, nor as readily serviced, as the components of the instant invention.
U.S. Pat. No. 4,735,357 to Gregory et al. teaches a sensor operated solenoid valve 82 that operates a valve member 80 which is retracted by the solenoid to indirectly open flow of water through the faucet (col. 8, lines 25-30, FIG. 4, 5). The patent mentions, but does not describe in detail, use of check valves and screens in the water inlets (col. 4, line 67 to col. 5, line 4). The temperature of the discharge water is regulated by temperature sensor 103 within the hot water supply pipe 75 which prevents scalding of the user when the hot water supply temperature exceeds a certain set point (col. 5, line 63-col. 6, line 10, FIG. 5-6). The interaction of the solenoid valve 82 and diaphragm 66 (FIG. 5) is described at col. 7, line 57 to col. 8, line 50. The patent does not describe the exact mode or location of mixing hot and cold water. It does not disclose components that are as readily serviceable as those if the instant invention.
Another solenoid operated faucet with sensor operation is U.S. Pat. No. 4,894,874 to Wilson, but in this faucet the solenoid operating valve 28 is below the sink deck where it is difficult to service.
Various other general details of solenoid operation in a sensor faucet are provided in U.S. Pat. Nos. 4,948,090 and 4,971,106, which are hereby incorporated by reference.
U.S. Pat. No. 5,618,023 to Eichholz, which is incorporated herein by reference, describes a battery pack for operating a sensor faucet, and more particularly, to a battery simulator that has the shape of a standard 6 volt lithium battery that converts an AC signal from a standard 110/120 volt power outlet to a DC signal for input at the battery terminals. However, the Eichholz battery simulator is complex and requires an expensive adapter to fit into the battery compartment. Thus, there is a need in the art to provide an AC power source that can be connected directly to the solenoid without needing a relatively expensive battery simulator.
The prior art therefore lacks a completely above deck, modular water faucet that can be worked on without removing the faucet from the deck and from which individual parts may be removed without removing, replacing, or otherwise altering other parts or the faucet itself.